The Animal Core Unit will be responsible for all genotyping, and backbreeding of KO mice, and in vivo experimentation conducted in BSL2-level Biocontainment as part of the Program Project. The services, listed below, are not provided by Department of Animal Medicine tiirough its per diem charge, which includes only food, water, bedding, and cage cleaning. All Program Project experiments will utilize viral antibody free (VAF) animals housed in a limited access facility designed to maintain the highest degree of cleanliness. These VAF animals will be moved to Biocontainment under the supervision of tiie animal core for all in vivo studies. The emphasis on strict limited-access biocontainment will preclude aoss-contamination and corruption of outcomes by unintended infectious agents. StricUy defined genotypes and consistent Neisseria infection are the core variables in tiie Program. The objectives and responsibilities of the Program Project Animal Core Unit are as follows: 1. Quarantine and husbandry an^angements and overall responsibility for the maintenance and verification of genotype of knockout mice in bred in VAF rooms. 2. Backbreeding knockouts and transgenic alleles onto the susceptible Balb/c background using genome scanning to facilitate speed congenic approaches to assure that animals are fully backbred. 3. Distribution of mice with defined genotypes to meet the needs of program investigators. 4. Infection and experimental manipulation of infected animals by trained personnel to assure the highest level of quality control and consistency in infection levels and outcomes. 5. Preparation of specimens (e.g. vaginal swabs, sponges, etc..) obtained under controlled conditions for cytokine analysis, colony counts and patiiology. 6. Development and standardization of assays to be used by all projects in the core to facilitate comparisons across projects for defined outcomes. In brief, ttie Animal Core will provide essential assistance to each project with the management of an extensive KO colony and execution of in vivo studies conducted under defined infectious conditions. It will maintain all records of animals and procedures and serve as a central facility for the cooperative efforts of the Program Project, assuring the highest possible quality control and data integrity.